Electrical switch

ABSTRACT

The invention comprises a snap-over switch comprising a casing housing in which is mounted a rocker arm carrying spaced movable contacts respectively engageable with a respective fixed contact on rocking movement of the arm by a pivoted switch actuator member through the intermediary of a leaf spring located on the rocker arm, the spring being shaped to provide a central portion in superposed spaced relation to the rocker arm and engageable by the switch actuator member and a looped portion at each end respectively engaging portions of the rocker arm extending from opposite sides of the support about which the arm pivots.

United States Patent Howe et al.

[ June 27, 1972 [54] ELECTRICAL SWITCH [72] Inventors: John Arthur Howe, Tollerton; Leslie Oliver Bryan, Stapleford, both of England [52] US. Cl. ..200/67 G FOREIGN PATENTS OR APPLICATIONS 1,276,776 9/1968 Germany ..200/67 G Italy ..200/67 G Sweden ..200/67 0 Primary Examiner-David Smith, Jr. Attorney-Philip E. Parker, Gordon Needleman, James R. O- Connor, John Todd and Hall & Houghton [57] ABSTRACT The invention comprises a snap-over switch comprising a casing housing in which is mounted a rocker arm carrying spaced movable contacts respectively engageable with a respective fixed contact on rocking movement of the arm by a pivoted switch actuator member through the intermediary of a leaf spring located on the rocker arm, the spring being shaped to provide a central portion in superposed spaced relation to the rocker arm and engageable by the switch actuator member and a looped portion at each end respectively engaging portions of the rocker arm extending from opposite sides of the support about which the arm pivots.

5 Claims, 3 Drawing Figures PKTEN'TEDJum 1912 9 FIG. 3.

ATTORNEY ELECTRICAL SWITCH This invention relates to an electrical switch of the kind operated by rocking movement of an actuator and it is an object of the invention to provide such a switch with improved operating mechanism.

The invention provides a snap-over switch comprising a casing housing two fixed contacts and a metal rocker arm carrying spaced movable contacts respectively engageable with a respective said fixed contact on rocking movement of the rocker arm, the rocker arm being pivotally mounted on a metal support a portion of which extends outwardly of the casing to form a terminal for attachment to a lead wire, a pivoted actuator member being provided having a projection engaging a leaf spring located on the rocker arm, the spring being shaped to provide a central portion in superposed spaced relation to the rocker arm and engageable by the said projection and a looped portion at each end respectively engaging portions of the rocker-arm extending from opposite sides of the support about which the arm pivots. I

One embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a sectional side view of a single pole changeover switch;

FIG. 2 is a plan view thereof; and

FIG. 3 is an end view.

As illustrated in the drawings, the switch comprises a casing 1 formed as a one-piece moulding of resilient or semi-resilient synthetic plastics. The casing is open at one end at which it is formed with a peripheral outwardly extending flange 2.

A cover 3 which serves as the actuating member is rockably mounted in the open end-of the casing by means of lugs 4 integral with the side walls of the cover and received in holes 5 in the opposed walls 6 and 7 of the casing.

A first plate-like contact terminal 8 is provided extending through a slot in the base 9 of the casing, the terminal including a portion 8a projecting inwardly of the casing and a portion 8b projecting outwardly and serving as a wiring tailpiece.

The inwardly extending portion 80 serves as a support post for a rocker arm comprising a metal strip 10, the medial portion of which is pivotally supported on the free end of the portion 8a so as to be rockable relatively thereto.

As shown, contacts 1], 12, are mounted on the underside of the opposite ends of the rocker arm l0. The upper side of the arm has a spring element 13 which has the general shape of a figure eight including substantially circular C -shaped end portions 14 connected by an intermediate portion 15 which is curved so as to provide a concave face directed away from the supporting post portion 8a.

A wedge-shaped member 16 depends integrally from the underside of the cover 3 and has an apex engaging the concave face of the connecting portion 15 of the strip.

A first fixed contact 17 is located on the base 9 of the casing at one side of the post portion 8a and in alignment with the contact 11 for engagement thereby. The contact 17 is electrically connected with a terminal 18 which extends through a slot in the base 9 of the casing to the exterior for connection with an electrical lead.

A second fixed contact 19 is located on the base 9 at the opposite side of the supporting post portion 8a in alignment with .the contact 12 for engagement thereby. The contact 19 is electrically connected with a terminal 20 which extends through a slot in the base 9 to the exterior of the casing for connection with an electrical lead.

As illustrated in FIG. 1, the switch parts are shown in one of the two operating positions of the switch, the contact 12 being in engagement with the fixed contact 19 so that a circuit is completed through the terminal 20, contacts l2, l9, rocker ann 10 and tenninal 8.

To move the switch into its second operating position, the actuating member or cover 3 is rocked by finger pressure about the lugs 4 so that the apex of the wedge-shaped element 16 is moved towards the left (as viewed in FIG. 1). During this movement the apex of the member 16 will ride over the portron 15 of the sprrng depressing this portion and when the apex passes the dead center position pressure will be transmitted to the rocker arm 10 through the left hand C-shaped portion 14 so as to rock the arm about the supporting post 8a whereupon the contact 12 will be moved into engagement with the contact 17. A circuit is now completed through the terminal 18, contacts 11, 17, rocker arm 10 and terminal 8.

It will be understood that the C-shaped portions of the spring 13 increase the resiliency and serve to maintain the portion 15 in engagement with the apex of the wedge-shaped member 16 at all times and further ensures a rapid snap-over movement of the rocker arm 10.

The switch is adapted for mounting in an aperture in a support and for this purpose the casing is formed with integral resilient arms 21', 22, extending from adjacent the base 9 to adjacent the open end of the casing, the respective arms being disposed at an angle to the end walls of the casing and being formed with shoulders 23, 24. The switch is assembled in the aperture in the support by presenting the base 9 to the aperture and exerting pressure to move the casing into the aperture until the flange 2 abuts the adjacent face of the support and the shoulders 23, 24, abut the opposite face.

During the movement of the casing 2 into the aperture, the arms 21, 22, will flex inwardly and when the free ends have passed the edge of the aperture, the arms will automatically spring outwardly to position the shoulders for resilient engagement with portions of the face of the support at opposed edges of the aperture.

We claim:

1. A snap-over switch comprisinga housing, two fixed contacts located in said housing, a fixed metal support terminal in said housing and a metal arm pivotally mounted on said support, said am carrying spaced contacts each engageable with a respective said fixed contact on rocking movement of said arm; a leaf spring disposed on said arm having free terminal ends adapted to but against the fixed metal support terminal, a switch actuator member pivotally mounted in said housing and provided with a projection engaging said leaf spring, said leaf spring being shaped to provide a central portion in superposed spaced relation to said ann and engageable by the said projection and a free looped portion at each end respectively engaging portions of said arm extending from opposite sides of the said support about which the arm pivots.

2. A switch as claimed in claim 1, wherein the said spaced contacts are located at the respective outer ends of portions of the said arm which are angular-1y disposed to one another.

3. A switch as claimed in claim 1, wherein the central portion of the said arm engaged by the said projection is concavely curved.

4. A switch as claimed in claim I, wherein each fixed contact is connected to a terminal extending outwardly of the housing for attachment to a lead wire.

5. A switch as claimed in claim 1, wherein said switch actuating member comprises the cover of said housing, the cover pivoting in apertures in the side walls of the housing. 

1. A snap-over switch comprising a housing, two fixed contacts located in said housing, a fixed metal support terminal in said housing and a metal arm pivotally mounted on said support, said arm carrying spaced contacts each engageable with a respective said fixed contact on rocking movement of said arm; a leaf spring disposed on said arm having free terminal ends adapted to but against the fixed metal support terminal, a switch actuator member pivotally mounted in said housing and provided with a projection engaging said leaf spring, said leaf spring being shaped to provide a central portion in superposed spaced relation to said arm and engageable by the said projection and a free looped portion at each end respectively engaging portions of said arm extending from opposite sides of the said support about which the arm pivots.
 2. A switch as claimed in claim 1, wherein the said spaced contacts are located at the respective outer ends of portions of the said arm which are angularly disposed to one another.
 3. A switch as claimed in claim 1, wherein the central portion of the said arm enGaged by the said projection is concavely curved.
 4. A switch as claimed in claim 1, wherein each fixed contact is connected to a terminal extending outwardly of the housing for attachment to a lead wire.
 5. A switch as claimed in claim 1, wherein said switch actuating member comprises the cover of said housing, the cover pivoting in apertures in the side walls of the housing. 